Agitator for a post-mix beverage dispenser

ABSTRACT

A post-mix beverage dispenser and refrigeration system including a water filter/purifier disposed within a refrigerated water reservoir for filtering carbonated water output from the dispenser carbonator en route to being mixed with flavor concentrate. The water reservoir also has a rotary agitator blade immersed therein with apertures to increase agitation.

This application is a continuation of application Ser. No. 943,124,filed on Dec. 18, 1986, now abandoned, which was a division ofapplication Ser. No. 737,413, filed on May 24, 1985, now U.S. Pat. No.4,660,741.

BACKGROUND OF THE INVENTION

The present invention relates to post-mix beverage dispensers which arecompact, portable and suitable for use in small offices or small volumelocations. More specifically, the present invention relates to a compactpost-mix beverage dispenser unit which may be disposed on a counter topin the above-mentioned environments and supplied with water from apitcher, syrup from disposable sealed packages and C0₂ for carbonationfrom refillable containers in a rapid and efficient manner. An accessoryattachment may allow connection to a building water supply for automaticrefill of the reservoir.

Heretofore, the majority of commercially-available post-mix beveragedispenser units have been designed for large volume commercial uses suchas in fast food restaurants. Because of these large volume uses, designcriteria have emphasized optimum cooling and dispenser speed rather thanlow unit cost, size and portability. Although some consideration hasbeen given to cost, size and portability even in these large volumecommercial units, the resulting unit designs are generally far tooexpensive, bulky and heavy for small volume use.

Some attempts have been made in the beverage dispenser industry toreduce the cost, size and weight of these units to make them availablefor use by the general public. However, the units designed heretoforehave lacked sufficient cooling capacity, dispensing efficiency, beveragequality and reliability as a trade off to achieving the aforementionedlow cost, size and portability needed for consumer acceptance.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to providea portable, low cost, miniature post-mix beverage dispenser unitsuitable for use in small offices or low volume locations.

It is another object of the present invention to provide a heat transfercircuit in a post-mix beverage unit operatively associated with amechanical refrigeration system which directly contacts and cools thewater, carbonator tank and syrup packages contained in the unit.

It is still a further object of the present invention to provide animproved agitator disc configuration for further increasing the coolingefficiency of the refrigeration system.

The objects of the present invention are fulfilled by providing apost-mix beverage dispenser including a supply of flavor concentrate, acarbonator for making carbonated water, a water reservoir for supplyingwater to said carbonator tank, means for refrigerating water in saidwater reservoir and means for mixing said flavor concentrate withcarbonated water output from said carbonator, the improvementcomprising:

an agitator assembly including a rotary agitator disc within the waterof said water reservoir, said disc having apertures therein permittingthe flow of said water therethrough, to thereby increase the amount ofwater agitation achieved compared to a similar shaped disc without saidapertures.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects of the present invention and the attendant advantagesthereof become more readily apparent by reference to the accompanyingdrawings, wherein:

FIG. 1 is a schematic diagram of the mechanical refrigeration system ofthe present invention;

FIG. 2 is a cross-sectional view of a water filter used in the system ofFIG. 1; and

FIGS. 3A and 3B are side elevation and top plan views of an improvedagitator assembly for use in the system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The post-mix beverage dispenser to which the improvements of the presenthave been applied is fully disclosed in U.S. Pat. No. 4,493,441 to Sedamet al., issued Jan. 15, 1985. A schematic diagram of the refrigerationsystem of that patent is illustrated in FIG. 11 thereof and is similarto portions of the system of FIG. 1 to be discussed hereinafter, likereference numerals referring to like parts.

The water supply, carbonation and refrigeration systems of the presentinvention are illustrated in the schematic diagram of FIG. 1. The waterreservoir WR is connected to the carbonator tank CT through the waterpump WP to pump water on demand from the reservoir to the carbonatortank under the supervision of a plurality of probes IP, MP and CO andsuitable electrical controls within box CB. That is, when power isturned on, pump WP will normally pump water from reservoir WR intocarbonator tank CT. However, if the water level falls below the minimumlevel of probe MP, the electrical circuitry provided within control boxCB will turn pump WP off and indicator light 58 on which signals theneed to refill the water reservoir WR.

Probes IP in water reservoir tank WR and carbonator tank CT sense thebuild-up of ice on the walls thereof, and when it exceeds apredetermined thickness whereby it covers probes IP, compressor CP isturned off via control box CB and control line 64. Probes CO in waterreservoir tank WR and carbonator tank CT are merely the common or groundconnections for the circuitry of both probes IP and MP.

Carbonator tank CT also has an additional pair of probes 66 and 68 toinitiate or terminate the operation of water pump WP, depending on thelevel of water present in carbonator tank CT. That is, when the waterlevel drops below probe 66, pump WP turns on to fill the carbonatortank, and when it reaches a maximum level at the position of probe 68, asignal is generated in the control circuitry within box CB via line 50to turn the water pump WP off. Thus, the respective probes in the waterreservoir WR and carbonator tank CT are all connected through theelectrical control circuitry in control box CB to either turn the waterpump WP on and off, or the refrigeration compressor CP via line 64.

With water present in carbonator tank CT, it operates in a conventionalmanner by mixing water from line 52 and C0₂ gas from line 56 within thetank CT and dispensing carbonated water through outlet line 54 to thedispenser valve assembly 18 wherein it is mixed with syrup from thesyrup packages SP.

As further illustrated, the mechanical refrigeration system includes acompressor CP, an evaporator C, and a condenser 32 connected in a closedrefrigeration loop. The evaporator C is disposed in contact with thewater reservoir WR to directly chill the water to be pumped to thecarbonator. As illustrated, a portion of the evaporator C, namelyportion 60, wraps around the carbonator tank CT to cool the same. Inaddition, another portion 62 of evaporator C may pass directly behindand in direct contact with cooling bracket 48 which surrounds syruppackages SP on three sides to cool the contents of those packages. Thus,the mechanical refrigeration system of the present invention may be inheat transfer relationship with all of the essential components of thepost-mix beverage to be dispensed prior to the mixing of thosecomponents within mixing nozzles 22. This assures that a post-mixbeverage is dispensed at a controllable and suitable temperature intocups or containers resting on drip tray 20.

FIG. 1 is a schematic diagram of the refrigeration system of thedispenser disclosed in the aforementioned U.S. Pat. No. 4,493,441 withthe addition of a water filter WF and a modified agitator disc AG.

In order to assure that no undesirable tastes or odors, which mightexist within the water of reservoir WR, permeate or effect the finalbeverage taste, a water filter WF is provided in carbonator water outletline 54. This filter WF preferably has an activated carbon filtrationelement which purifies carbonated water passing therethrough by removingundesirable odors and tastes.

It is a discovery of the present invention that an optimum location forthe water filter WF is within the water reservoir WR in a recirculationpath (outlet line 54) of carbonated water from carbonator tank CT.However, improved cooling can also be obtained if the filter WF is inthe water reservoir in series with the still water output line betweenpump WP and carbonator CT.

The advantages of the optimum location are at least three-fold. Firstly,this location results in increased cooling efficiency of the systemcarbonated water and thus the final beverage because the filter WF isimmersed within the chilled water of reservoir WR. Secondly, the life offilter WF is increased because carbonated water has a lower pH(approximately 4.2) than still water, and this lower pH tends toincrease the life of activated carbon filters. Thirdly, the lower pHgreatly increases the chlorine removal capacity of an activated carbonfilter. In fact, a reduction of one full point of pH gives theappearance of doubling chlorine removal capacity by adsorption. Chlorineremoval capacity decreases with a decrease in water temperature.However, the increase in removal capacity achieved by the lower pH ofcarbonated water more than offsets the decrease caused by the lowertemperature of the filter environment.

In contrast to this optimum location of filter WF, prior attempts toplace a water filter outside of reservoir WR in series with the stillwater input line 52 to carbonator tank CT have resulted in inefficientcooling, the filter WF acting as a heat sink or absorber of the ambienttemperature, which is then transferred to the water. In addition, thelife of the activated carbon filtration element is decreased when it isused to filter still water having a higher pH.

The details of a preferred filter structure are illustrated in FIG. 2.Filter WF is preferably a conventional activated carbon filtermanufactured by the Cuno Filter Division of AMF, Inc. Filter WF has anouter, substantially cylindrical housing 71 which contains an upperfilter material F1, conventionally known as "MICROKLEEN" and a lowerfilter material F2 of activated carbon. A top fitting 70 is providedincluding inlet orifices 76 for carbonated water from carbonator CT (thepreferred embodiment) or still water from the water pump WP. Fitting 70is designed to fit into a socket of an input/output manifold and supportblock (not shown). O-ring seals 72 isolate input openings 76 from anoutput opening 78 in tube 74. It can be seen that water to be filteredpasses through input openings 76; down through filter materials F1, F2;and up tube 74 through outlet opening 78 en route to the dispenservalves.

The cooling efficiency of the system of the present invention is furtherincreased by using an agitator assembly in water reservoir WR with arotary disc AG with a series of apertures AG1 therein. This agitatorassembly is schematically illustrated in FIG. 1 as extending intoreservoir WR. The assembly includes an electric motor AM suitablysupported in the dispenser cabinet, a motor shaft S and the disc AG withholes AG1 therein. The details of the blade AG structure and holes AG1are illustrated in detail in FIGS. 3A and 3B. The disc AG of theagitator assembly is preferably substantially planar in side elevationand circular in top plan view. This shape minimizes splashing, ascompared to an agitator with conventional impeller blades thereon, whenthe water level in WR approaches the level of disc AG. However, a flat,disc-like shape does not agitate as well as conventional impellerblades. In order to increase the agitation (circulation of water) whileminimizing the degree of splashing, the disc AG of the present inventionis provided with holes AG1. These holes AG1 increase agitation andturbulance to a significant extent. It has been found that the provisionof holes AG1 significantly increases water agitation and hence coolingwith essentially no increase in noise level or splashing of water evenat low water levels in reservoir WR.

Additional cooling efficiency may be achieved by using thermal masticbetween contiguous parts where heat transfer is desired, and insulationof parts exposed to ambient or increased temperatures of othercomponents.

It should be understood that a preferred embodiment of the dispensercabinetry and system components of the beverage dispenser of the presentinvention have been described herein, but that modifications may be madeas would occur to one of ordinary skill in the art without departingfrom the spirit and scope of the present invention.

What is claimed is:
 1. In a post-mix beverage dispenser including asupply of flavor concentrate, a carbonator for making carbonated water,a manually refillable water reservoir for supplying water to saidcarbonator, means for refrigerating water in said water reservoir andmeans for mixing said flavor concentrate with carbonated water suppliedby said carbonator, the improvement comprising:an agitator assemblyincluding a rotary agitator disc within the water of said waterreservoir, said disc having continuous uninterrupted smooth planarsurfaces on both first and second sides thereof with aperturesvertically formed therein permitting the flow of said watertherethrough, to thereby increase the amount of water agitation andcooling achieved compared to a similar shaped disc without saidapertures.
 2. The dispenser of claim 1, wherein said increased wateragitation and cooling occurs at a plurality of water levels within saidmanually refillable water reservoir, thereby preventing splashing ofsaid water at each of said plurality of water levels and particularly ata water level substantially even with said disc.
 3. The dispenser ofclaim 1, wherein said disc increases said water agitation and coolingwithout splashing above a surface level of said water, thereby reducingnoise and providing a clean dispenser environment.
 4. The dispenser ofclaim 1, wherein said disc further prevents splashing above a surfacelevel of said water, including a water level substantially even withsaid disc.
 5. In a post-mix beverage dispenser including a supply offlavor concentrate, a carbonator for making carbonated water, a manuallyrefillable water reservoir for supplying water to said carbonator, meansfor refrigerating water in said water reservoir and means for mixingsaid flavor concentrate with carbonated water supplied by saidcarbonator, the improvement comprising:an agitator assembly including arotary agitator disc within the water of said water reservoir, said dischaving continuous uninterrupted smooth planar surfaces on both first andsecond sides thereof with apertures vertically formed therein permittingthe flow of water therethrough upon actuation of said disc, to therebyprevent splashing of water by said disc regardless of a water levelwithin said water reservoir.
 6. The dispenser of claim 5, wherein saidagitator assembly increases the amount of water agitation and coolingachieved compared to a similar shaped disc without said apertures.